Transcript Mon 19 January 15 -The Begining of Life

Izben C. Williams, MD, MPH
Instructor
9/15/2014
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Developmental Journey
 There are immensely complicated, mysterious, and
beautiful transformation (biological, psychological
and social) that take place between conception
and old age
 The period from CONCEPTION TO BIRTH sets
the stage for all other development that we
undergo as humans
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Some Prenatal Influences I
 Genetic factors play a prominent role in
determining the biological potential of a fetus.
 The process of development is a sequential
unfolding of normal events (and disorders) that
are genetically determined
 In about 40% of children with ADD heriditary
factors are the basis
 Down syndrome (trisomy 21), Klinefelter syndrome
(XXY) and Fragile X syndrome are also genetically
determined conditions
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Some Prenatal Influences II
 Sex and survival factors:
 At conception 160 M : 100 F
 At birth the ratio is aprox. 100 M : 100 F.


The surviving males have a higher risk for some degree
of brain dysfunction
ADD ten times more frequent in males
 Gestational age, birth-weight, maternal health, and
perinatal factors may predict outcome
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Intrauterine Influences on
development I
 The intrauterine environment can significantly
affect fetal brain development, and hence all
future actions (behaviors)
 Animal models used to mimic adverse intra uterine
conditions in humans
 Intrauterine insults to the brain may be acute or
chronic
9/15/2014chronic
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Intrauterine Influences II
 Even brief periods of hypoxemic compromise can
have significant effects on the fetal brain causing
neuronal loss and cerebral white matter damage
 Subtle brain injury can occur, for example to a
particular class of neuron, and this can have a
significant effect on the function of a specific system,
(eg hearing, vision)
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Intrauterine Influences III
 Chronic mild placental insufficiency can result in
long term deficits in neuronal connectivity
 Repeated acute exposure to an inflammatory agent
results in diffuse subcortical white matter damage
and in some cases periventricular necrosis.
 The timing and severity of these prenatal insults
determines outcomes, in terms of the severity of the
damage and the regions of the brain affected.

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Smoking and Alcohol
 Placenta mediates fetal growth and influences
long-term health
 Placenta to birth-weight ratio is regarded as an
indicator of the quality of placental function
 Maternal prenatal smoking and alcohol
consumption may influence fetal growth by either
directly or indirectly altering the function of the
placenta, and hence the development of the fetus.
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Role of the placenta in fetomaternal exchanges
Reminder of placental role:
 Exchange process via membranous exchange
mechanisms
 The fetal lung
 Nutritive and excretory functions
 Protective function and Immunological barrier
 Endocrine function and protein transfer
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Some noxious trans placental
influences
 Some microbes can cross the placental barrier
despite its efficiency:
 Sexually transmitted diseases (treponema
palidum, HIV, Neisseria Gonorrhea
 Feto-toxic infections (rubella, toxoplasmosis,
cytomegalovirus, herpes simplex genitalis)
 Drugs (most antibiotics, corticosteroids,
teratogenic drugs such as Roacutane and
Thalidomide
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Neonatal Capacities
 At birth, the infant is pre-adapted to be cared for
by the mother by the presence of attachment
behaviors.
 Initial attachment behaviors (eg. crying and
clinging) increase the likelihood of maternal care
and assist the infant in attaching to the mother
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Neonatal Capacities
 The neonate possesses a number of innate simple
reflexes
1. Moro reflex or startle reflex: flexion of
extremities in response to sudden stimulation
2. Palmar grasp reflex
3. The rooting and sucking reflexes (both aid in
feeding the infant
4. The Babinski reflex
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Development Sequences
 Key: Consult table in text for schedule of motor,
vocal, and sensory development sequences of
the infant
 Cognitive maturation: by age 18 to 24 months a
child is capable of elementary trial-and-error
reasoning.
 For example a child will attempt to place a square
object into a square opening of a form box after
trying to insert it into the circular and triangular
opening
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Birth and Post-partum
 Two separate patients: Mother and Infant
 Infant status
 APGAR
 Primitive reflexes (Startle, sucking, grasp, Babinski)
 Maternal status
 Physical status
 Psychological status
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Theories of Development
 Several theories, derived primarily from clinical
experience and experiment.
 Perhaps the best known systems in use today, are:
 Freud’s psychoanalytic theory,
 Piaget’s Cognitive developmental stages
 Ericson’s Psychosexual stages
 The theories mostly identify developmental
landmarks
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Concepts of Child Development
 There is a lawfulness to all natural development,
which serves as a framework within which we can
assess and understand children and adults
 Epigenesis: The development of an embryo from
the successive differentiation of an originally
undifferentiated structure (Epigenetic= after genes)
 Physical Epigenesis
 Behavioral Epigenesis
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Developmental Tasks
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Multiple developmental tasks
 The pre-school child traverses several motor,
social, and verbal/cognitive developmental zones
by age six.
 Key: See schedule of age-related developmental
tasks, in text. Important to have an appreciation
of these milestones
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Developmental Screening
 There are many Developmental Screening-andAssessment (S&A) Instruments for young children
ages birth through five years
 Link to S&A instruments:
http://www.nectac.org/~pdfs/pubs/screening.pdf
 These instruments emphasize Psychological,
Social, Emotional and Physical Development
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Psycho-Social Development I
 The principle psychological task of the first year of
life is the formation of intimate differentiated
attachment to mother of caregiver.
 Failure of the infant to develop this specific early
attachment may result in later defects in the
capacity for empathy and for close warm reciprocal
relationship.
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Psycho-Social Dev’nt II
 The social smile is an early marker of the beginning
development of a specific differentiated relationship,
as are the preferential vocalization, visual pursuit and
anticipatory gesturing of the 5-month-old infant in the
presence of the mother
 Endogenous smiling develops from an innate reflex
response at birth
 Exogenous smiling a response to the form of a face – 8
weeks
 Preferred social smile a response to mother’s face 16
weeks
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Psycho-Social Dev’nt III
 Stranger anxiety begins at ~ 8 months
 Object relations (psychoanalytic theory)
 Response to Maternal deprivation/separation
 Play: its role and significance
 Autonomy and self awareness
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Psycho-Social Dev’nt IV
 Sociocultural factors:
 Innercity: increases risk of psyc. disorders
 ADD: twice as high in low income families
 Psychosocial, or sociocultural, retardation:
deficient language, speech and cognitive skills
associated with relative deficiency in adequate early
stimulation (usually lower socio economic class)
 Weaning from bottle shorter in middle class
 toilet training favors lower class
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